windjammer vs sailing vessel

windjammer and sailing vessel both are nouns.

Word	Noun	Adjective	Verb	Adverb
windjammer	Yes	No	No	No
sailing vessel	Yes	No	No	No

As nouns, sailing vessel is a hypernym of windjammer; that is, sailing vessel is a word with a broader meaning than windjammer:

windjammer: a large sailing ship
sailing vessel: a vessel that is powered by the wind; often having several masts

Other hypernyms of windjammer include sailing ship.

windjammer (noun)	sailing vessel (noun)
a large sailing ship	a vessel that is powered by the wind; often having several masts